[Coco] RAINBOW vinyl records?

[Arthur Flexser]

It's been quite a while since I looked at the Super Extended Basic ROM code,
but my recollection is that the bugs were neither all that numerous nor
particularly serious.  It is definitely coded more sloppily than the
Microsoft CoCo ROMs, true, but that mostly takes the form of wasted bytes
rather than bugs.

Microware made the decision to have Super Extended Basic run in RAM, above
Disk Basic.  Given that decision, the 6K space used for the picture could
not be used for Basic code;  it is accessed from the internal rom by
switching memory modes, and is not normally in the memory map at all.  (The
same is true of the 40/80 column screen memory, though in that case the
switch is accomplished switching in normally mapped-out RAM segments
temporarily.)
Microware did leave a K or two of RAM space unused above Super Extended
Basic that could have been used for additional features;  I assume Tandy
specified what features they wanted and Microware found they could easily
cram them into the available space with room left over both in the RAM map
and (to a much bigger extent) in the internal ROM.  In the latter case, they
shoved a picture in there for lack of incentive to do anything fancier.

None of this has any bearing on people buying OS-9,  which makes no use
whatsoever of the Microware code.

Art
On Fri, Aug 14, 2009 at 5:17 PM, Christian Lesage <hyperfrog at gmail.com>wrote:

> William Schaub wrote:
>
>>
>>> Not only that but if I recall correctly it loads from tape (and floppy) a
>> lot faster than some other machines contemporary to it like the C64. which
>> had amazingly slow disk and tape. (there are hacks to speed up the 1541 but
>> still its pretty slow)
>>
> The C64 had nonetheless much better graphics and sound capabilities than
> the first two CoCos (and even the CoCo 3, to some extent). And with the
> FastLoad cartridge, the 1541 was quite usable. I'd say the main problem with
> the C64 was its ROM: the Kernel and the BASIC interpreter could have been
> made much better. Perhaps Commodore decided that it would become a gaming
> platform, and as such, it didn't need to have an advanced BASIC interpreter.
> The CoCo, on the other hand, had poor graphics and sound support, so it
> needed a feature that would appeal to some people: Microsoft Extended BASIC
> and Disk BASIC. It's a shame Microware left so many bugs behind when they
> patched Extended BASIC for the CoCo 3. They had enough room to hide a 6KB
> picture in the ROM... IMHO, that space could have been better used! The
> buggy ROM could have been part of a scheme to lure customers into buying a
> disk drive, OS9... and then a 512KB add-on memory board. I didn't buy the
> latter back in the day; I had already spent $200 on the CoCo, $100 on a
> monochrome monitor, $400 on a disk drive and $100 on OS9 (Canadian
> dollars)... Yet, I would have needed that damn 512KB board to be able to do
> any kind of serious work with that system. I was pissed off, to say the
> least. Retrospectively, I think I should have bought an Amiga! Now folks,
> please don't flame me... I still have a CoCo and I think it's a fun machine
> to mess around with. (I also own a very cool C64 and an ultra cool Amiga...
> [grin].)
>
> Christian
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